Mathematics of the bandpass function

How can I see the math behnd the bandpass function? Is it butterworth or what is the formula used? The help function dosn't seem to help. I would like to know the background mathematics behind the function.

Answer 1

[Jan]

The documentation explains:

bandpass uses a minimum-order filter with a stopband attenuation of 60 dB and compensates for the delay introduced by the filter.

Did you use the debugger already to examine, what is calculated? Set a breakpoint in the first line of bandpass.m and step through the code line by line. This should reveal all details.

Answer 2

[Star Strider]

When I used it, the bandpass function designed an efficient elliptical filter. You can simulate it with the ellipord, ellip, zp2sos, and filtfilt functions.